Offshore Wind Foundation Fabrication
Offshore wind foundations are heavy, fatigue-critical and installed in a weather window. Everything that matters about them — weld quality, dimensional accuracy, coating integrity — has to be right before the structure leaves the quay, because there is no practical correction afterwards.
Meritus sources foundation structures and components from Chinese fabricators, with inspection weighted towards the fatigue-critical welds and the coating systems that determine service life.
Scope we cover
Monopiles and pile sections; transition pieces including flanges, brackets and secondary steel; jacket foundations, piles and sleeves; suction bucket structures; boat landings, ladders, platforms and J-tubes; anode systems and corrosion protection; surface preparation and marine coating systems.
Fatigue-critical welding
Foundation welds are governed by fatigue, so the acceptance criteria are tighter than general structural work and the NDT extent is higher. We review welding procedures against the fatigue class assumed in design, verify NDT coverage rather than accepting a sampling rate, and require that repair welds are recorded and re-inspected — unrecorded repairs are the single most common finding in foundation audits.
Coating and corrosion protection
Splash-zone and submerged coating systems are inspected at each stage: surface preparation standard, profile, coat thickness and holiday detection. Anode mass, placement and continuity are verified against the CP design, since under-protection shows up as a survey finding years later. Every order runs through the same quality chain: shop pre-qualification, material traceability against mill certificates, in-process and final inspection, and a documentation pack released before shipment.
Failure modes we inspect for
Repair welds in fatigue-critical zones that were made and not recorded. NDT sampled rather than applied to the specified extent. Anode mass and continuity assumed from the drawing rather than verified on the structure. Splash-zone coating applied over a preparation standard that was signed but not achieved. And weld profiles that satisfy soundness criteria while falling short of the fatigue class assumed in design.
How an order runs
Enquiry and specification review; shop shortlisting against the actual scope rather than a general vendor list; quotation with the inspection plan priced in, not added later; kick-off with agreed hold and witness points; in-process inspection at those points; final inspection, document pack release and shipment; arrival support if anything is queried. For foundations the repair-recording protocol and NDT extent are agreed before the first production weld, and coating hold points are set per stage rather than at completion.
Frequently asked questions
What foundation types can be sourced from China?
Monopiles and pile sections, transition pieces with their flanges and secondary steel, jacket foundations with piles and sleeves, and suction bucket structures.
Why is repair-weld recording so important?
Because fatigue life is calculated on assumed weld quality. An unrecorded repair removes the evidence that the assumption still holds, and it is the most common finding in foundation audits.
How is corrosion protection verified?
Coating stages are inspected individually — preparation standard, profile, thickness, holiday detection — and anode mass, placement and electrical continuity are checked against the cathodic protection design.
Does Meritus coordinate certification?
Yes, including class and certifying-body involvement to the extent the project requires, alongside the fabricator's own EN 1090 and ISO certification.